AIR DRYING EPOXY RESIN LACQUERS

1,235,167. Epoxy resin coating. FARBENFABRIKEN BAYER A.G. 11 Sept., 1968 [29 Sept., 1967], No. 43196/68. Heading B2E. [Also in Division C3] Metal, e.g. steel, and other surfaces are coated with an air drying lacquer which comprises: (A) a modified or unmodified OH- containing polyepoxide derived from bisphenol A in which at least 50% of the OH groups have been esterified by reaction with one or more light-fast monoisocyanates, and (B) aliphatic, cycloaliphatic or heterocyclic amino compounds or with aromatic compounds in which the amine groups are aliphatically bound which compounds contain at least 3 hydrogen atoms attached to amino nitrogen atoms. Examples relate to diglycidyl ethers of bisphenol A having epoxide equivalents of 475 and 1185. The polyepoxide may be modified by reaction with polyamines, polycarboxylic acid anhydrides, polyalcohols, phenol, urea or melamine resins or diisocyanates to such an extent that it is still soluble in lacquer solvents. Suitable monoisocyanates are methyl isocyanate, methoxymethyl isocyanate, cyclohexyl isocyanate, benzyl isocyanate or monoisocyanates obtained by reacting 1 mol of a diisocyanate and 1 mole of a monoalcohol or monoamime. Suitable amines are ethylenediamine, diethylenetriamine, triethylenetetramine, pentaethylenehexamine, 2, 4-diamino-2- methyl pentane, bis (p-aminocyclohexyl)-methane, m-xylenediamine, N(#-aminoethyl)-piperazine, basic polyamidoamines or dimerised linoleic fatty acids with diethylenetriamine and triethylenetetramine and basic imidazolines of C 10-20 mono- and di-carboxylic acids and diethylene triamine, triethylenetriamine or pentaethylene hexamine or mixtures of the above mentioned polyamines. The ratio of NH equivalents in the polyamine to epoxide equivalents in the polyepoxide may be between 0.8 and 1.4. Reference has been directed by the Comptroller to Specification 1,139,422.